| abstract |
The present invention relates to a combustion product of a fuel such as formic acid or acetic acid generated when a fuel having a carbon / hydrogen ratio (element ratio) of 0.4 or less or a fuel containing an oxygen-containing hydrocarbon compound is used in an internal combustion engine. Provided are a lubricating oil composition for an internal combustion engine that is excellent in tolerance such as base number, particularly in retention performance of hydrochloric acid method base number, and means therefor. A lubricating oil composition for an internal combustion engine using a fuel having a carbon / hydrogen ratio (element ratio) of 0.4 or less or a fuel containing an oxygen-containing hydrocarbon compound, comprising a mineral oil base oil and / or Alternatively, a lubricating base oil composed of a synthetic base oil, (A) a metal salt of a phosphorus-containing acid represented by the general formula (a) or (b), 0.01 to It is set as the lubricating oil composition characterized by containing 0.2 mass% and (B) metallic detergent. [Selection figure] None |